In the related art, there is a grille apparatus that includes a plurality of cover members (long grille plates) provided in an opening portion (grille opening portion) of a front grille, and can change the degree of opening of the front grille by turning the cover members (for example, refer to JP58-139519UM-A (Reference 1)).
That is, for example, while a vehicle is travelling at a high speed, it is possible to improve aerodynamic performance (for example, a “Cd value”) by decreasing the degree of opening of the front grille, and limiting the flow rate of air flowing into an engine compartment (closed state). During engine start-up, it is possible to reduce a warm-up time of an engine by decreasing the flow rate of air to be introduced to a radiator. When the temperature of the engine tends to increase, it is possible to manage the engine temperature appropriately by increasing the degree of opening of the front grille, and increasing the flow rate of air flowing into the engine compartment (open state).
However, in the configuration of turning the cover members, a large number of moving points become a problem in improving the reliability of the apparatus. To solve the problem, for example, a grille apparatus disclosed in JP2012-148705A (Reference 2) is configured such that a single cover member is slidably provided in front of a grille opening portion, and the grille opening portion is opened and closed. Accordingly, it is possible to improve reliability by reducing the number of moving points.
However, the configurations in the related art have a problem that a certain amount of time is required to complete an opening and closing operation because a stroke of the opening and closing operation, that is, a movement distance of the cover member is large. In addition, the configurations require an accommodation space for the cover member and a large space for the disposition of a moving mechanism. Since there is a problem in that the thickness of the cover member in a vehicle longitudinal direction increases when the cover member is deployed in front of the grille opening portion, there is still room for improvement in this regard.